<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
    /* 后代选择器 只要有都会被选中 */
    .nav a {
        color: burlywood;
        background: chocolate;
    }
    /*子代选择器  */
    .nav > a{
        color: cornsilk;
        background: darkcyan;
    }
    
    </style>ni
    
</head>
<body>
    <div class="nav">
        <a href="#">我是儿子</a>
        <p>
            <a href="#">我是孙子</a>
        </p>
    </div>
    <!-- div. -->
    <div class="nav1"></div>
    <div id="nav2"></div>
    </ul>
</body>
</html>